Band brake



' B. J. MICHAEL BAND BRAKE Filed. May 9, 1923 m 0 Fig.2. 12 9 '8 a l [47w Benjqmin d. Michud I Patented Apr. 8, 1924.

" UNITED "STATES" 1,489,451 PATENT OFFICE;

BENJAMIN JOHN MICHAEL, OI LLANELLY, WALES 3m BRAKE.

Application filed Kay 9, 1828. Serial No. 637,863.

lliy invention is intended more particularly to be ap lied to the bandbrakes of motor cars and will be described as I intend to apply it toFordcars.

In these cars it is rather troublesome to adjust the brake band when, byreason ofwear .of the friction surfaces, it has become unduly slack andmy invention if applied devised so that my invention may be rea tosuch'cars will at once overcome this defeet.

Further, in view of the fact that a very large number of-Ford cars are1n use, the constructional form of my invention, hereinafter describedwith reference to the accompanying drawing, has been especially 1 Yadapted for use in such cars without requiring serious refionstruction.

In the accompanying drawing Fig. 1 is a front elevation; Fig. 2, is asectional view of Fig. 1; andFig. 3, is an end. view looking from leftto ,right of Fig. 1. v

The numeral 4 indicates a. brake drum, and 5 the brake band thereon,thelatter being provided with the usual upstandmg bifurcated ends 6, 7

8 is a bearing to support the spindle 9, that engages in the'slots in 6and 7, and has its end '10 screw-threaded to receive a nut 11. On theright hand end of the spindle 9 will be fixed the usual lever (notshown) by the actuation of which the ends 6 and 7 are forced together(through the intermediary of cam surfaces) as is well understood; thereis also the usual spring 12 that tends to separate the parts 6 and 7 soas to slacken the band on the drum when reverse movement of the leverreferred rmits this. I I ixerl to or made integrally with the nut 11, isa ratchet toothedrim or wheel'13,

and interposed between the nut and the forked end 6 is a washer 14: thathas a bore of sufiicient size as to allow the screwed end of the spindle9- to slide freely through it. The said .washe'r is provided i with ablock 15 that fits snugly in the slotcf the end 6 so as topreventthewasher rotating and at its upper part, the washer is formed orprovided with a, sort of housing in which is mounted a pawl 16, toengage the ratchet teeth of the rim 13 on the nut 11', and which housingalso contains aspring 17 that serves to maintain the pawl in enga mentwith said teeth.

lso mounted on the spindle 9 is a colhr 18 that is slidable on thespindle but compelled to rock or oscillate therewith, by a feather 19which fits in a. roove in the spindle and which collar and t e nut 11are formedwith interengaging ratchet teeth which, as will be furtherexplained, allow the collar to rotate in one direotion'independently ofthe nut". but compel both to move together in the opposite direction.

The; collar has mounted on it a. washer 21 having arms extendingtherefrom, to which and the part 14, springs 22 are connected that serveto maintain the collar normally engaged with the nut.

The number of teeth on the rim 13 is dependent ,upon (1) the angulardistance through ,fwhich the spindle normally is rocked ,fwhe-n the band5 is brought from the brake-off to the brake on position (and viceversa), and (2) the maximumfurther angular distance the said spindleshall be permitted to rock, before a taking up of the excess slack(brought about by wear of the 'band 5 on the drum 4 is to take place.

For example, if the spindle rocks in normal conditions through an angleof 6 degrees, and it is desirablethat the maximum angular movement shallbe very slightl more than 7 degrees before the excess slack of the brakeband is taken up, I would form 'teeth on the rim 13, because thedistance apart of the teeth would represent slightly more than 7degrees. The ratchet teeth on t the collar 18 (and of course also ontheface of the nut) will equal in number those on the rim 13.

The operation of the device is as follows: As premised, by way ofexample, when the brake is new and the band 5 properly will drop intoengagement with the nexttooth. (Vixen thereafter the spindle 9 rocks;hack to its ncrmal'position the-pawl 16 will prevent the nut 11mov-ingiwith' the spindle; hut-the latter will carry With it the collarhe' s on the drum (i, it will require an ange lar movement at sixtlegrees to operate the, hand; to its brake of and. brakehn ositiens.

At this time the nutll is roe etl with the indle 9 by reascnof'theengagement I therewith of the toothed collar 18, and the pawl 16 Willremain in engagement against the peripheral lace of the tooth-wherein;it happens to 'he situate as this rocking place. 7 r v I a h As Weartakes place between the brake hand. and the drum, the angular distance,

' 18 (its teeth riding over those on the face of the nut) thecollarfthus being moi' ed a distancekslightly greater thanthe lengthofthe ratchet teeth, and'on the next s'uc wetting rocking movement of thespinclle 9* in the direction to tighten .upthe brake band, the collar 18will rotate the'fnut 1lthrough the distance of one toothg and to thatextent will scr w up'said not on the spindle 9 andtherehy take up theexcess slack in the brake -band.' i

It will he understoocl'that the longer the Vagainstrotation, a ratchetdevice to connect greater the distance from tooth to tooth) as. comparedwith theangular distance. nor- 'nzaily required to rock the spindle 9from .thejhrali e ofito the brake on position, the greater will be theamount of wear that will have to take place between the brake hand andthe drum, before-the automatic ad- ,jinstment, totake upthe excess slackin the hanci, takes place, and, of course, the con verse also holdsgood-4?; being borne in mind that the length of the teeth must notin'zany case be less and in practice should always-he at any rate slihtly greater than the distance the spindle is rocked as stated.

' As already pointeclout theeonstrnctional f orm illustrated of myinvention 'is designed to permit its application with little trouble tobraking mechanisms, of the 'charaster-stated, already in nse, but myinvention is-not limited in its scope thereto. Further, although I haveproposed to apply it toQbra-king means used on motor vehicles, it willbe obvious that its application is not limited=to that but may beapplied to any tighteneci up on a hrake'rlrum,

braking means in Whiclia brake band is What I claim is:

In a hand brake,- a brake'flruim a brake band thereon having bifurcatedends, 'a. H spindle passing through and supported so as to i'ock in:said ends-and having a screw v threaded end, a nuton said spindle torotate thereon, a block'on said spindle'held the block and the nut, asecond nut sliclable onsaldspincl'le, a ratchet device to connect bothsaidv nuts and means exterior of said ends to yieldin'gly maintain thenuts in en- :gagement. ratchet teeth on the r1in-13 are (i. entheBENJAMIN JOHN MICHAEL.

